harridan vs nagger

harridan and nagger both are nouns.

Word	Noun	Adjective	Verb	Adverb
harridan	Yes	No	No	No
nagger	Yes	No	No	No

As nouns, nagger is a hypernym of harridan; that is, nagger is a word with a broader meaning than harridan:

harridan: a scolding (even vicious) old woman
nagger: someone (especially a woman) who annoys people by constantly finding fault

Other hypernyms of harridan include common scold, nag, scold, scolder.

harridan (noun)	nagger (noun)
a scolding (even vicious) old woman	someone (especially a woman) who annoys people by constantly finding fault